Apparatus and method for producing a core

摘要

A method is disclosed of producing a highly consolidated sand core. The method includes the steps of closing metal mold halves (13a, 13b) to define a core space (14), charging gas-curable molding sand into the mold space, evacuating the core space to a pressure of 2 - 100 Torr, introducing air into the evacuated core space at an air pressure that increases at a rate of 50 - 600 kg/cm<2> /sec to apply a pressure to the surface of the gas-curable molding sand to obtain a high charging density; and introducing a curing gas into the core space to harden the molding sand. <IMAGE>